Lewis & Short

nŏvendĭālis, e, adj. [novem-dies], nine-day, of nine days.

  1. I. That lasts nine days, a nine-days’ festival, which was solemnized on the occasion of a prodigy announcing misfortune (esp. a shower of stones): novendiale sacrum, Liv. 1, 31; 21, 62; 23, 31; 25, 7; 26, 23; 27, 37 et saep.: sacrificium, id. 38, 36, 4: novendiales feriae, Cic. Q. Fr. 3, 5, 1; cf.: novendiales feriae a numero dierum sunt dictae, Paul. ex Fest. p. 176 Müll.
  2. II. That takes place on the ninth day; of offerings and feasts for the dead, which were celebrated on the ninth day after the funeral: novendiale dicitur sacrificium quod mortuo fit nonā die quā sepultus est, Porphyr. ad Hor. Epod. 17, 49; cf.: novendialia, ἔννατα ἐπί νεκροῦ ἀγόμενα, Gloss. Philox.; cf. also Serv. Verg. A. 5, 64.
    These solemnities were also called, subst., nŏvendĭal, is, n.: nescio utrum inveniatur, alicui sanctorum in Scripturis celebratum esse luctum novem dies, quod apud Latinos novendial appellant, Aug. Quaest. in Heptat. 1 Quaest. 172: novendialis cena, the funeral banquet held on the ninth day, Tac. A. 6, 5: Novendiales pulveres ( = recentes), Hor. Epod. 17, 48; v. Orell. ad h. 1.
    Prov.: exstincto populo etiam novendialis tarde venit, said of one who brings assistance when too late, Ps.-Quint. Decl. 12, 23.